Hearing instruments, i.e., devices that assist the hearing impaired, designed for complete or partial insertion into the user's ear canal, have a shell or housing that holds various components. One such component is the receiver, the element that generates the sound heard by the instrument's user. The sound is carried from the receiver by a receiver tube affixed to a port on the receiver to an opening (the receiver tube hole) in the tip of the shell, the portion of the hearing instrument positioned in the ear canal towards the eardrum.
During assembly, the receiver and its receiver tube are inserted into the shell, receiver tube first, and the tube is passed through the receiver tube hole. Once the receiver is in place inside the shell, anchored by a support, any excess portion of the receiver tube protruding from the shell is removed.
During assembly, the receiver tube is inserted into the shell and aimed towards the receiver tube hole. Occasionally, the end of the tube misses the receiver tube hole and catches on the inside of the shell. In that instance, the receiver tube must be pulled out and reinserted in an attempt to pass the tube through the receiver hole.
An Improved Configuration for the Inside of the Shell
The problem mentioned above may be minimized by providing an inwardly-sloping contour inside the shell of the hearing instrument. In particular, the interior of at least a portion of the shell comprises a chamber having planar or conical surfaces or inwardly curving or convex surfaces that guide the receiver tube towards the tip of the shell and the receiver tube hole.
Depending on the size and length of the hearing instrument, the shell may contain more than one such chamber. For example, where there are two chambers, the receiver tube is inserted into and through the first chamber and the tube then passes through an optional interconnecting passage and into and through the second chamber. A stopper having dimensions greater than the interconnecting passage may be provided on the receiver tube. When the stopper meets the end of the first chamber, the tube will not travel further into the shell, fixing the location of the receiver in the shell. A stopper may also be provided for a shell having a single chamber.
The design discussed here will improve the assembly process. An additional benefit achieved by the configurations discussed here is that walls of the shell are reinforced, reducing any tendency of the walls to vibrate.